Ah hah hah. Just go through the very old posts of some of our mods, back to when they were just wee noobies. You'd be surprised how these folks were ever considered.
Don't worry, it's cool. It's not a crime to be curious.
Anyway, moderators are generally chosen. Whenever a need for a new moderator arises, such as an old one quits or an area becomes particularly spammy, the current moderators discuss who might make a good new moderator. We look at those mature, intelligent members active in the area that needs moderation as the prime candidates, and after a particular member is decided upon, we send them a PM offering the position. Sometimes they accept, and sometimes they don't. And that's how it's done.